In the earlier days of colorectal surgery for malignant tumors of the lower third of rectum, the operation of choice was the abdomino-perineal resection (APR) in which the sigmoid, the rectum, and the anus were excised leaving the levator ani muscle complex intact in both sides. In this way, the specimen resembles an hourglass due to the characteristic “waist” in the middle [
8]. However, given the incomplete resection rate and the high local recurrence compared to low anterior resection of rectum (LARR) [
9] colorectal surgical community has nowadays moved towards the ELAPE. The last one has proved to be superior in oncologic terms compared to conventional APR. Its superiority relies largely on the fact that apart from the sigmoid, rectum, and anus, the levator ani complex is removed as well, providing a cylindrical (waist-free) specimen, reducing by this mean, tumor involvement at circumferential resection margin. As with APR, the patient ends up with a permanent colostomy. In fact, this is the main disadvantage of both operations affecting patients’ quality of life. In an attempt to reduce the frequency of permanent colostomy in low rectal cancer surgery a better selection of patients has been suggested. So, in cases with very low rectal lesions, no involvement of the external anal sphincter or the levator ani muscle complex, and adequate preoperative sphincter function and continence, ISR is preferred as it preserves anal sphincteric function to some extent. This is achieved by entering the intersphicteric space and dissecting the internal from the external anal sphincters, leaving the later almost intact [
4]. Attempts for function-preserving procedures with partial external anal sphincter resection have been described in cases with external anal sphincter infiltration [
10]. Moreover, in a special sub-group with unilateral puborectalis muscle infiltration and adequate sphincteric function, HLE was proposed as an attempt to keep anorectal function and achieve oncologic adequacy. A comprehensive summary of the current surgical procedures for low rectal cancer is presented in Table
2. Noh et al. proved that robotic/laparoscopic HLE yield oncologic results comparable to those of a standard ELAPE, while offering the patient the unparalleled advantage of avoiding a permanent colostomy [
11]. According to them, an open approach is not feasible since the surgeon lacks of a clear view of the surgical field. Since the open approach still remains the standard of care in rectal cancer surgery, we tried to perform HLE by this way. Herein, we show that an open approach not only is feasible but also can potentially be served as a promising alternative for laparoscopic or robotic HLE since the latter two forms are not widely popularized among the surgical community yet. Moreover, being able to perform the open approach is important even among those surgeons who are trained on the laparoscopic and/or robotic techniques because knowing this alternative would allow them to overcome difficulties that would require the conversion of the surgery (from laparoscopic to an open one) with minimum oncologic cost for the patient. However, laparoscopic and robotic procedures overcome the open one concerning the enhanced vision and appreciation of the field [
12,
13]. It is reasonable some concerns to be raised regarding the oncologic radicality since anatomic borders among LAM, PRM and the deep part of the EAS are not very clear [
14]. Indeed, the heated debate regarding the anatomy of anal canal dates back to 1897. At that time, it was identified that some muscle fibers of the “pubococcygeus,” instead of inserting into the coccyx, loop around the rectum, continue on to the opposite side and thus form a different muscle, the PRM. Since then, the EAS is perceived as a three-part structure with the PRM being part of the LAM; PRM is located just below the LAM and EAS extends down. The very close relation of the deep part of the EAS and PRM has led some authors to consider them as one muscle [
15,
16]. Baring this debate in mind, in order to enhance the oncologic safety of the procedure, the deep part of ipsilateral to tumor EAS is included in the surgical specimen. Moreover, a macroscopic margin 10 mm of the transection line from the lower border of tumor ensures the oncologic adequacy further. The oncologic value of the open approach seems to be equal to that of the other approaches, as proved by the pathology of the specimen and the MRI at the fourth post-operative week that shows clearly the right aspect of anorectal junction free of tumor and the absence of ipsilateral LAM (Fig.
2a, b). The major advantage of the open procedure is the maintenance of continence, as proved by the postoperative clinical assessment of patient after restoring large bowel continuity (post-op Wexner score, 7) and the anorectal manometry findings (which in our case, revealed a fair anorectal function). In fact, the efficiency of the operated sphincter is acceptable since only a part of the deep portion of the EAS is removed. Preservation of internal anal sphincter at the contralateral to tumor side might also add to the whole sphincteric function and particularly at rest and during the sleep.
Table 2
Summary of the current trends in surgical procedures for low rectal cancers
Abdomino perineal resection (APR) | Sigmoid, rectum, and anus are excised sparing the levator ani muscles complex (hourglass-like specimen) | Lesions at the lower third of the rectum | Poor oncologic outcome, permanent colostomy | |
Extralevator abdomino-perineal excision (ELAPE) | APR + excision of the levator ani muscles complex (cylindrical specimen) | Lesions at the lower third of the rectum | Permanent colostomy | |
Intersphicteric resection (ISR) | Surgical plane in the intersphicteric space, dissection of the internal anal sphincter, saving the external sphincter | • Lesions at the lower third of the rectum that do not involve the levator ani muscles • Good pre-operative sphincter function and continence | May not be suitable for patients that have undergone neoadjuvant treatment | |
Subtotal intersphincteric resection/partial external sphincteric resection | ISR + partial external anal sphincter resection | • Lesions of the lower third of the rectum invading part of the external anal sphincter • Good pre-operative sphincter function and continence | Not applicable for lesions invading the levator ani muscle | |
Hemilevator excision (HLE) | Resection of the levator ani muscle, the deep part of external anal sphincter and the internal sphincter ipsilaterally. The contralateral ones are preserved | • Lesions at the lower third of the rectum involving the levator ani muscle in one side • Good pre-operative sphincter function and continence | Not applicable for cancers circumferentially infiltrating levator ani complex | |